From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: To: 9fans@cse.psu.edu Subject: Re: [9fans] QTCTL? From: erik quanstrom Date: Wed, 31 Oct 2007 19:54:25 -0400 In-Reply-To: <8ccc8ba40710311526o4a5e55a7wf04f12844d4d4b66@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Topicbox-Message-UUID: e2758aa6-ead2-11e9-9d60-3106f5b1d025 > If the file is "decent", the cache must still check out > that the file is up to date. It might not do so all the times > (as we do, to trade for performance, as you say). That means > that the cache would get further file data as soon as it sees > a new qid.vers for the file. And tail -f would still work. the problem is that no files are "decent" as long as concurrent access is allowed. "control" files have the decency at least to behave the same way all the time. if one goes down the road of client-side caching, i think concurrency issues need to be taken seriously. otherwise it's like having a multiprogramming kernel without locks. - erik